With the continuous expansion of a mobile communications network and miniaturization of base stations, the number of network elements that an operator needs to maintain increases sharply, and higher maintenance cost is required. Therefore, a self-organizing network (SON, self-organizing network) is proposed, and automation is implemented as far as possible in the phases of planning, deployment, and operation and maintenance on the mobile communications network to save the operation cost.
As requirements for mobile communications increase sharply, available spectrum resources are relatively insufficient. Therefore, it is more and more important to flexibly allocate a spectrum to improve network capacity and spectrum efficiency. In addition, a change of the operating environment (for example, increase of cell traffic and uneven load distribution) causes a mismatch between spectrum allocation and load distribution and causes decrease of network performance.
Spectrum allocation, as a planning problem, is usually based on a long-timescale network environment, for example, a site location, average bandwidth capacity, spectrum efficiency, and large-scale signal attenuation. The conventional static spectrum allocation remains unchanged within a long period after planning and optimization are completed in the early phase of network construction, and spectrum replanning is not required until obvious decrease of network performance or until network reconstruction.
The conventional dynamic spectrum allocation aims at minimizing the overall interference strength within a network, and dynamic spectrum allocation is performed according to the actual measured and collected interference strength in the network operation period. For example, dynamic spectrum management (DSM, Dynamic Spectrum Management) dynamically manages and allocates spectrums according to the current operating environment of the network, and can improve the level of matching between spectrum resources and load distribution, thereby improving network performance.
However, the conventional spectrum allocation affects all cells in the network and causes unnecessary overheads.